For commercial seed to be sold in Canada, the seed being sold has to be rendered non viable. That is to say the seed must be in a form that will not germinate. Whole commercial seed can be sold to a primary processor holding a valid processing license with Health Canada. It is then the primary processors responsibility to process the seed into a non viable state, and maintain records proving such. It is the primary processors responsibility to have THC levels established and documented, for their products before being sold.
That way the primary processed products that flow into the secondary manufacturers and consumers hands carry a certificate of acceptable THC levels so that no further testing is required at the secondary level, thus eliminating a lot of additional testing, and testing costs and paper work.